Field of the Invention
The present invention relates to a current application device which applies a test current to a semiconductor element, and a method for manufacturing the semiconductor element using the same.
Description of the Related Art
Generally, a semiconductor element testing device used in testing the semiconductor element is configured to have a current application device which applies a test current for testing electrical characteristics of the semiconductor element to the semiconductor element. Conventionally, as such current application device, the one in which the test current is applied via a contacting section (a probe) having a projection group comprising a plurality of projections that are arranged at a constant interval (for example, refer to Japanese patent Application Laid-Open No. 2007-218675).
In such current application device, the test current is applied while pressing the contacting section against the semiconductor element with a spring, such that each projection constituting the projection group contacts an electrode and the like of the semiconductor element. At this time, a reaction force that the contacting section receives from the semiconductor element from the contact is dispersed to each projection, so that it becomes possible to delay a progress in abrasion of a gold metal layer and the like at a leading end of the projection.
By doing so, it becomes possible to maintain a stable electrical contact between the semiconductor element and the contacting section during application of the test current for a long period of time. Further, by doing so, it is conceivable that application of large test current is possible, from the contact portion contacting well with an electrode and the like of the semiconductor element with each projection, and also from the test current being dispersed and applied via each projection.
In a screening test for power semiconductor elements such as an IGBT (Insulated Gate Bipolar Transistor) or power MOSFET and the like, large current is applied to a contact region within an active region of the semiconductor element. In this case, it is conceivable that it is preferable to use the contacting section having the projection group as is explained above, and distribute and apply the test current uniformly with each projection, so as to be capable of applying the large current uniformly throughout the whole contact region as much as possible.
In this case, number of projections necessary may be determined, on the basis of a magnitude of necessary test current, and a critical current value that can be applied from one projection. Further, it becomes possible to set an arrangement pitch of the projections at the contacting section so as to correspond to an area of the contact region in the active region, according to the number of projections.
However, in a case where such contacting section is used, it has been discovered that there is an inconvenience that a current value flowing in a part of the projections reaches the critical current value by only supplying a current smaller than the test current with necessary magnitude to the contacting section, so that the test current with the necessary magnitude cannot be applied.